Embodiments of the disclosed technology pertain to a thin film transistor (TFT) array substrate and a manufacturing method thereof.
Thin film transistor-liquid crystal displays (TFT-LCDs) employ a variable electric field applied onto a liquid crystal layer to control the orientations of liquid crystal molecules and therefore control transmittance of the liquid crystal layer to conduct display of images.
In general, a liquid crystal panel comprises a backlight module, a lower array substrate, an upper color filter substrate and a liquid crystal layer filled into the space formed by combining the two substrates together. Each pixel unit on the array substrate comprises a pixel electrode and a TFT switch element, and the application and amplitudes of the voltage on the pixel electrode are controlled respectively by the gate signals over the gate electrode, connected with a gate line, of the TFT switch element and by the data signal over the source electrode, connected with a data line, of the TFT switch element. The common electrode on the upper color filter substrate cooperates with the pixel electrodes on the lower array substrate to control the orientations of the liquid crystal molecules with the variable electric field produced therebetween. On the array substrate, storage capacitor lines (Vcom lines) that are parallel with and on the same level as the gate lines can form storage capacitors with pixel electrodes therebetween for maintaining the state of the liquid crystal molecules of the corresponding pixel units before arrival of a next driving signal.
An array substrate may be implemented in a dual-gate configuration, which can effectively reduce the amount of data line integrated-circuit (IC) terminals (i.e., connecting parts with a driving IC) and realize the benefits of lowering costs. In order to avoid a greenish defect, a panel with the dual-gate configuration typically adopts a reticulated Vcom line configuration, as shown in FIG. 1. In FIG. 1, the array substrate comprises gate lines 1, data lines 2. Vcom line IC terminals 3, Vcom lines 4 and pixel units 5. The Vcom line IC terminals 3 are the connecting parts of the Vcom lines with a driving IC. From FIG. 1, the Vcom lines 4 for all the pixel units are electrically connected in both the horizontal and the longitudinal directions to form a network configuration, and further the Vcom line IC terminals in the longitudinal direction are arranged alternatively with the data line IC terminals in the longitudinal directions.
In particular, in FIG. 1, the IC terminals from the left side to the right side comprise a Vcom line IC terminal 31, a data line IC terminal 21, a Vcom line IC terminal 32, a data line IC terminal 22, a Vcom line IC terminal 33, a data line IC terminal 23, and a Vcom line IC terminal 34. Given there are N data lines, there would be N+1 Vcom line IC terminals. This alternative configuration gives rise to waste of IC terminals and also results in reduction of aperture ratio of the pixel unites.